splashscreen.dart

// make sure you add the dependency to your pubspec.yaml file.
// dependencies:
//   splashscreen: ^1.2.0

// make sure that your splash file dimension 
// is height: 1280 × width: 800 pixels


import 'package:flutter/material.dart';
import 'package:splashscreen/splashscreen.dart';
void main(){
  runApp(new MaterialApp(
    home: new MyApp(),
  ));
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return new SplashScreen(
      seconds: 14,
      navigateAfterSeconds: new AfterSplash(),
      title: new Text('Welcome In SplashScreen',
      style: new TextStyle(
        fontWeight: FontWeight.bold,
        fontSize: 20.0
      ),),
      image: Image.asset('images/yoursplashfile.png'),
      backgroundColor: Colors.white,
      styleTextUnderTheLoader: new TextStyle(),
      photoSize: 100.0,
      onClick: ()=>print("Flutter Splash"),
      loaderColor: Colors.red
    );
  }
}

class AfterSplash extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
      title: new Text("Welcome In SplashScreen Package"),
      automaticallyImplyLeading: false
      ),
      body: new Center(
        child: new Text("Done!",
        style: new TextStyle(
          fontWeight: FontWeight.bold,
          fontSize: 30.0
        ),),

      ),
    );
  }
}